Transmission routes of hepatitis B virus infection in chronic hepatitis B patients in The Netherlands

The Netherlands is a low endemic country for hepatitis B virus (HBV). Rotterdam, a city in The Netherlands harbors a large group of chronic hepatitis B (CHB) patients of which most are born abroad. The study included 464 consecutive CHB patients who were reported to the Municipal Public Health Service in Rotterdam from January 1, 2002 to September 15, 2005. The HBV genotypes, possible transmission routes of infection and travel history of CHB patients born in The Netherlands, were compared with those CHB patients living in The Netherlands but who were foreign-born, taking into account the ethnicity of the mother. Of the 464 patients with CHB infection, 14% were Dutch-born and 86% were foreign-born. The CHB patients in the Dutch-born group had genotypes A (35%), B (15%), C (11%), D (37%), and G (2%). In the foreign-born group, the distribution of genotypes was A (20%), B (15%), C (11%), D (40%), and E (15%). In the Dutch-born group, sexual transmission accounted for a larger proportion of infections (P < 0.0001) compared to the foreign-born group, whereas perinatal transmission is reported to be higher in the foreign-born group and in the Dutch-born group with a foreign mother. The genotypes of the chronic HBV strains determined corresponded well with the HBV genotypes expected from the countries of origin of the patients or their mothers. Genotypes A and D are predominant in CHB patients in The Netherlands.